iPhone 5 Lightning port dynamically reassigns pins

Apple's Lightning USB cable doesn't use a simple symmetrical design.

A recent analysis of Apple's Lightning USB cable shows that the pins on the plug aren't arranged symmetrically, suggesting that the Lightning port can dynamically reassign signals to each pin on the fly. "Dynamic assignment of the pins is the only way for the USB data to be routed" over the cable, according to boutique cable maker Double Helix Cables.

While the standard USB power is routed symmetrically, so that it always aligns with the same pin on the Lightning connector, the data pins are not.

"Take top pin 2 for example," Double Helix's Peter Bradstock told AppleInsider. "It is contiguous, electrically, with bottom pin 2. So, as the plug is inserted into the iPhone, if you have the cable in one way, pin 2 would go into the left side of the jack, flip it the other way and the same pair of pins is going to match up with the other side of the jack (as the electrical contacts in the iPhone's jacks are along the bottom)."

As Apple noted during the iPhone 5 introduction, the Lightning port was designed as a purely digital interface that could adapt to various output needs now and in the future. So the dynamic pin assignment design makes sense—it's the only way Lightning could work with USB 2.0, HDMI, VGA, or even possibly USB 3.0—though it does seem somewhat overkill for the needs of USB 2.0. Perhaps the varied pin routing discovered by Double Helix lets the iPhone 5 recognize the type of cable plugged in.

There is a chip in the wire too, some people are speculating that it might be what handles the dynamic assignment, or course others are speculating that it could be there to basically prohibit non apple licensed cables and/or adapters.

There is a chip in the wire too, some people are speculating that it might be what handles the dynamic assignment, or course others are speculating that it could be there to basically prohibit non apple licensed cables and/or adapters.

There is a chip in the wire too, some people are speculating that it might be what handles the dynamic assignment, or course others are speculating that it could be there to basically prohibit non apple licensed cables and/or adapters.

Can't it be both?

Yes, obviously it can. I suspect it might actually be both to be honest. I was merely separating them as competing "motivation" theories.

There is a chip in the wire too, some people are speculating that it might be what handles the dynamic assignment, or course others are speculating that it could be there to basically prohibit non apple licensed cables and/or adapters.

Can't it be both?

Yep, it's both. Though I'm sure people will come up with clones (worst case, you just borrow the whole chip), the economics of third party cables totally change if their COGS is $3 versus $0.25. With Apple cables retailing for $20, I'm likely to buy cloned cables for $5 each; I'm not likely to buy them at $12.

It's neat, don't get me wrong, but still not worth continuing with iphone for me. If it works for all the cool crap it *could* do then I look forward to either imitation or pushing forward as a new standard connector in the future, but something tells me Apple's going to be contrary as usual and try to come up with an even more proprietary connector to force on it's users. Maybe they'll even change the screws again when you take it in for service like they did way back when on the iphone 3 series...

Apple's simple, elegant design mocked for being "too few pins to be useful for anything important" is, in fact, more complicated than initially guessed?

Shocked, I say.

This is not complicated and has absolutely nothing to do with the pins. The same concept is used in several adapters, including (at least on Macs now) ethernet adapters to allow using any cable as a crossover cable. Anyone with the least amount of EE background should have immediately guessed that the adapter was made to operate this way, and - especially given the keynote announcement - if this guy was actually surprised to see this implementation he's an idiot or an amateur.

You are a bit of a tool for pretending that people have a problem with the adapter for having "too few pins" when what everyone actually is pissed about is that Apple invented yet another stupid proprietary adapter and rejected the standard for no real benefit.

Apple's simple, elegant design mocked for being "too few pins to be useful for anything important" is, in fact, more complicated than initially guessed?

Shocked, I say.

This is not complicated and has absolutely nothing to do with the pins. The same concept is used in several adapters, including (at least on Macs now) ethernet adapters to allow using any cable as a crossover cable. Anyone with the least amount of EE background should have immediately guessed that the adapter was made to operate this way, and - especially given the keynote announcement - if this guy was actually surprised to see this implementation he's an idiot or an amateur.

You are a bit of a tool for pretending that people have a problem with the adapter for having "too few pins" when what everyone actually is pissed about is that Apple invented yet another stupid proprietary adapter and rejected the standard for no real benefit.

Well put! Feed that troll facts and they'll eventually go away.

For me (and literally everyone I've talked to) the issue is a practical one: I need consistency across my iDevices. You want to change the connector? Fine. Invent a rounder wheel. But at least have them in abundant (and affordable) supply, and make darn sure 3rd parties have access; because if I get even the slightest whiff of a monopoly on accessories, I'm switching teams.

This "boutique cable" hawker is sure getting a lot of media exposure. First the chip in the cable speculation and now this. Not a bad way to drive business to your wannabe Monster cable operation. $150-900 for a freaking USB cable. Give me a break, how does anyone think this guy is a credible source.

In a year or two, the lightning connector will be ubiquitous enough that most people will forget to care, the exception being those that are still so ticked that they feel they have to be pissed on other people's behalf.

As for use as a "licensed accessory" enforcer, vigilance is most certainly called for, but it seems strange to be up in arms about something that hasn't happened yet.

William Topping wrote:

Over engineered cables.

Crap maps.

Get your priorities right Apple.

Are you suggesting that all other development on iPhone should stop until maps meets competitive (or at least acceptable) standards? Its possible to lose efficiency by assigning too many staff to work on something (too many cooks in the kitchen,) plus there are different specialties that aren't necessarily compatible (ex: hardware engineering vs software development.) The course of action you imply would leave a lot of folks (like the ones in hardware engineering that developed the "over engineered cables") sitting on their butts while maps get fixed.

Apple's simple, elegant design mocked for being "too few pins to be useful for anything important" is, in fact, more complicated than initially guessed?

Shocked, I say.

This is not complicated and has absolutely nothing to do with the pins. The same concept is used in several adapters, including (at least on Macs now) ethernet adapters to allow using any cable as a crossover cable. Anyone with the least amount of EE background should have immediately guessed that the adapter was made to operate this way, and - especially given the keynote announcement - if this guy was actually surprised to see this implementation he's an idiot or an amateur.

You are a bit of a tool for pretending that people have a problem with the adapter for having "too few pins" when what everyone actually is pissed about is that Apple invented yet another stupid proprietary adapter and rejected the standard for no real benefit.

There were plenty of articles and especially comments on articles stating that USB 3.0 requires 9 pins and the lightening connector only has 8 so therefore it can't support USB 3.0. Unfortunately not everyone has an EE background and the tasty mis-information that Apple shot themselves in the foot by only including 8 pins was spread all over the place.

Apple's simple, elegant design mocked for being "too few pins to be useful for anything important" is, in fact, more complicated than initially guessed?

Shocked, I say.

This is not complicated and has absolutely nothing to do with the pins. The same concept is used in several adapters, including (at least on Macs now) ethernet adapters to allow using any cable as a crossover cable. Anyone with the least amount of EE background should have immediately guessed that the adapter was made to operate this way, and - especially given the keynote announcement - if this guy was actually surprised to see this implementation he's an idiot or an amateur.

You are a bit of a tool for pretending that people have a problem with the adapter for having "too few pins" when what everyone actually is pissed about is that Apple invented yet another stupid proprietary adapter and rejected the standard for no real benefit.

Actually there have been many posts on the various iPhone 5/iOs6 threads, even on Ars, about just this. You would be shocked at the amount of ignorance demonstrated with regard to this adapter. It seemed that anyone with half a brain explaining the dynamic nature getting shouted down as an Apple fanboy. I even saw one person saying that it would only do USB since there were too few pins left over for anything else. Before you call someone a tool for pretending something you might want to make sure that the facts back you up.

Apple invented yet another stupid proprietary adapter and rejected the standard for no real benefit.

So you're saying a nondirectional plug and future expandability is literally no real benefit?

I'd bet far sighted people who want to charge their phone without first finding their glasses might disagree. Also what happens in a few years when USB 2 isn't the mobile hotness anymore? Is it better to use a standard that changes every few years or a proprietary solution that adapts for a decade? Reasonable people can disagree, but they don't dismiss other viewpoints out of hand.

I'd bet far sighted people who want to charge their phone without first finding their glasses might disagree. Also what happens in a few years when USB 2 isn't the mobile hotness anymore? Is it better to use a standard that changes every few years or a proprietary solution that adapts for a decade? Reasonable people can disagree, but they don't dismiss other viewpoints out of hand.

Micro USB 3.0 would put them in a legitimately superior position compared to every other phone out there. As it is now they might as well charge $29 more for the phone itself.

Micro USB 3.0 would put them in a legitimately superior position compared to every other phone out there. As it is now they might as well charge $29 more for the phone itself.

How so? I don't see any practical advantage to USB 3 in a current phone apart from faster charging due to the higher power rating, and there are workarounds to provide higher power ratings with USB 2. Also, have you seen a USB 3 connector? They're not exactly elegant (or particularly desirable IMO).

There's no reason to put logic in the middle of a cable except to keep it proprietary.

Thunderbolt uses transceivers at each end of the cable, just so Apple can sell more cables? No, it's because that makes the system media-agnostic. In high speed networking, you often see cabling with integrated logic (although we see them as transceivers with integrated cables)

if this guy was actually surprised to see this implementation he's an idiot or an amateur.

He's clearly an amateur regarding electronics, if you read his blog entry. It's a little disappointing to see so many blogs pick up his teardown (including Ars), but I guess he was the first to get at it, so he gets the prestige.

There's no reason to put logic in the middle of a cable except to keep it proprietary.

Active cables can be longer and/or thinner than dumb cables. e.g. DisplayPort cables can be active without being proprietary. The spec only goes up to 3 meters over a dumb cable, but 33 meters with an active cable.

There's no reason to put logic in the middle of a cable except to keep it proprietary.

When you're dealing with extremely high datarates (40Gbps, 100Gbps, etc...) the chip-in-cable makes sense because the timings become so tight that the speed of light is a major limiting factor.

For this cable...not so much.

Well, even at 10 Gbps per lane, things get pretty tough, which is the frequency that most current 40/100 Gbps solutions operate at.

Lightning can operate at 5.4 Gbps, which isn't too tough, but you still need chips to deMUX the MyDP signal and output USB or HDMI, a DAC to output analog audio or VGA, and something to perform voltage regulation for attached chargers/accessories.

How so? I don't see any practical advantage to USB 3 in a current phone apart from faster charging due to the higher power rating, and there are workarounds to provide higher power ratings with USB 2.

Superior speed, faster charging, and most importantly full backwards compatibility.

These are all non-issues. Superior speed makes no difference if you can't saturate the inferior speed standard. As I said, there are workarounds for faster charging via USB 2. You can get two amps if you need to (which is higher than the 900 ma from USB 3). Finally, you don't think Apple will offer full backwards compatibility when they add new capabilities to this?

Quote:

NickN wrote:

Also, have you seen a USB 3 connector? They're not exactly elegant (or particularly desirable IMO).

I find Apple's cheap plastic junk to be ugly. Beauty is in the eye of the beholder, after all.

Then you'll be sadly disappointed by the cheap plastic junk used for micro USB 3.

How so? I don't see any practical advantage to USB 3 in a current phone apart from faster charging due to the higher power rating, and there are workarounds to provide higher power ratings with USB 2.

Superior speed, faster charging, and most importantly full backwards compatibility.

After some thought, I'm thinking if you really believe full backwards compatibility is the most important thing you should be all over the Lightning port. Dynamic pin assignment probably makes it much more future-proof than just about anything else out there. They're basically sacrificing low cost for greater future compatibility. How great is that?